Induction of Uterine Cyclooxygenase by Leutenizing Hormone and Estradiol is an Important Determinant of Bovine Luteolysis

摘要

Termination of the functional bovine corpus luteum is associated with a precipitous fall in peripheral plasma progesterone which is induced by a pulsatile release of prostaglandin F-2 alpha (PGF) from the late luteal phase uterus. The production of uterine PGF from arachidonic acid is greatest in endometrial cells 2-5 and 15-17 days post-ovulation. Similarly exposure of uterine endometrial cells to estradiol 17 beta or to lutenizing hormone (LH) results in a significant increase in LH receptors, cyclooxygenase-2 (COX-2) and PGF at 2-5 and 15-17 days post-ovulation. It is therefore suggested that hormonal regulation of uterine COX-2 by pulses of estradiol and LH may play a role in bovine luteolysis.